Endothelial AMPK activation induces mitochondrial biogenesis and stress adaptation via eNOS-dependent mTORC1 signaling
Division of Cardiovascular Medicine, Department of Medicine; UMass Metabolic Network
Biochemistry | Cell Biology | Cellular and Molecular Physiology | Molecular Biology
Metabolic stress sensors like AMP-activated protein kinase (AMPK) are known to confer stress adaptation and promote longevity in lower organisms. This study demonstrates that activating the metabolic stress sensor AMP-activated protein kinase (AMPK) in endothelial cells helps maintain normal cellular function by promoting mitochondrial biogenesis and stress adaptation. To better define the mechanisms whereby AMPK promotes endothelial stress resistance, we used 5-aminoimidazole-4-carboxamide riboside (AICAR) to chronically activate AMPK and observed stimulation of mitochondrial biogenesis in wild type mouse endothelium, but not in endothelium from endothelial nitric oxide synthase knockout (eNOS-null) mice. Interestingly, AICAR-enhanced mitochondrial biogenesis was blocked by pretreatment with the mammalian target of rapamycin complex 1 (mTORC1) inhibitor, rapamycin. Further, AICAR stimulated mTORC1 as determined by phosphorylation of its known downstream effectors in wild type, but not eNOS-null, endothelial cells. Together these data indicate that eNOS is needed to couple AMPK activation to mTORC1 and thus promote mitochondrial biogenesis and stress adaptation in the endothelium. These data suggest a novel mechanism for mTORC1 activation that is significant for investigations in vascular dysfunction.
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Citation: Nitric Oxide. 2016 May 1;55-56:45-53 Epub 2016 Mar 14. Link to article on publisher's site
AICAR, AMPK, Endothelial dysfunction, Mitochondrial biogenesis, Nitric oxide, Rapamycin, eNOS, mTORC1
Li, Chunying; Reif, Michaella M.; Craige, Siobhan M.; Kant, Shashi; and Keaney, John F. Jr., "Endothelial AMPK activation induces mitochondrial biogenesis and stress adaptation via eNOS-dependent mTORC1 signaling" (2016). UMass Metabolic Network Publications. 46.